need some serious dev advice on this

First of all, if this is not the proper place to pose this question, please redirect me to a better one

I'm beginning to develop an app which will take me quite some time due to its complexity, but to make it really usefull and widespread I'm planning to release it across all the BB devices: bb smartphones - playbook - bb10

I have, however, 2 big question marks and would like some clarification on how to go about with it, so that I don't waste time in doings things which later can not be used or won't work as expected:

Will we ever have a way to easily sync app data across these devices? or should we rely from the start on an external (web) service?

the app will make use of contacts and calendar data. I know that, for now, we still don't have access to that API in PB and BB10, but I guess we will sooner or later. The question is, will it play well with a sync service working across devices? What's your advice on this?

Re: need some serious dev advice on this

I am hopeful, though less than optomistic that what already exists on the BES/ActiveSync side of things can be brought over to the Consumer side. RIM Cloud Serivces should handle this, and it should be included in some push to users of existing BBs.

Re: need some serious dev advice on this

Are contacts & calendar data the only type of data being considered here?

For 1) it seems like you are describing a classic cloud-based service, where web APIs can serve as the mechanism for transferring data between devices (not just BB, but other platforms too including desktop, of course).

A direct communication channel may eventually be possible through a custom Bluetooth extension. No one has created one yet for BB smartphones, and we don't yet have the architecture in place for 3rd party extensions on BB10 (soon I hope), but I would expect if these pieces were in place, you may be able to transfer data between paired devices.

Both have their pros and cons. A cloud service may be easier to maintain and apply changes to, as well as being easier to use from a user's perspective. However the perceived security may be a concern for users ("What are you doing with my contacts / calendar data?").

For 2) the data would need to be serialized in a format supported by the given sync mechanism. Whether that is text-based (JSON / XML) or binary.

Re: need some serious dev advice on this

If you're hoping of something like an "iCloud" API, where apps can easily store data and access it accross devices: sadly there hasn't been anything announced yet by RIM - at least according to my knowledge.